나는 이런 종류의 문제 를 잠시 동안 싸우고 있었고, 나는 신뢰할 수있는 해결책을 생각해 냈다고 생각합니다.

그것은 그 확실히 알고 꽤 어려운 this.getActivity()반환하지 않을 nullA에 대한 Fragment당신의 코드를 철회 할 수있는 충분한 시간 제공 네트워크 동작의 모든 종류의 상대하고 특히, Activity참조.

아래 솔루션에서 나는이라는 작은 관리 클래스를 선언합니다 ActivityBuffer. 본질적으로 이것은 class소유에 대한 신뢰할 수있는 참조를 유지 하고 유효한 참조가있을 때마다 유효한 컨텍스트 내 Activity에서 실행을 약속 합니다. 의는 즉시 경우 UI 스레드에서 실행 예정이다 그 때까지 그렇지 않으면 실행이 지연되고 있습니다 준비가되어 있습니다.RunnableActivityRunnableContextContext

/** A class which maintains a list of transactions to occur when Context becomes available. */
public final class ActivityBuffer {

    /** A class which defines operations to execute once there's an available Context. */
    public interface IRunnable {
        /** Executes when there's an available Context. Ideally, will it operate immediately. */
        void run(final Activity pActivity);
    }

    /* Member Variables. */
    private       Activity        mActivity;
    private final List<IRunnable> mRunnables;

    /** Constructor. */
    public ActivityBuffer() {
        // Initialize Member Variables.
        this.mActivity  = null;
        this.mRunnables = new ArrayList<IRunnable>();
    }

    /** Executes the Runnable if there's an available Context. Otherwise, defers execution until it becomes available. */
    public final void safely(final IRunnable pRunnable) {
        // Synchronize along the current instance.
        synchronized(this) {
            // Do we have a context available?
            if(this.isContextAvailable()) {
                // Fetch the Activity.
                final Activity lActivity = this.getActivity();
                // Execute the Runnable along the Activity.
                lActivity.runOnUiThread(new Runnable() { @Override public final void run() { pRunnable.run(lActivity); } });
            }
            else {
                // Buffer the Runnable so that it's ready to receive a valid reference.
                this.getRunnables().add(pRunnable);
            }
        }
    }

    /** Called to inform the ActivityBuffer that there's an available Activity reference. */
    public final void onContextGained(final Activity pActivity) {
        // Synchronize along ourself.
        synchronized(this) {
            // Update the Activity reference.
            this.setActivity(pActivity);
            // Are there any Runnables awaiting execution?
            if(!this.getRunnables().isEmpty()) {
                // Iterate the Runnables.
                for(final IRunnable lRunnable : this.getRunnables()) {
                    // Execute the Runnable on the UI Thread.
                    pActivity.runOnUiThread(new Runnable() { @Override public final void run() {
                        // Execute the Runnable.
                        lRunnable.run(pActivity);
                    } });
                }
                // Empty the Runnables.
                this.getRunnables().clear();
            }
        }
    }

    /** Called to inform the ActivityBuffer that the Context has been lost. */
    public final void onContextLost() {
        // Synchronize along ourself.
        synchronized(this) {
            // Remove the Context reference.
            this.setActivity(null);
        }
    }

    /** Defines whether there's a safe Context available for the ActivityBuffer. */
    public final boolean isContextAvailable() {
        // Synchronize upon ourself.
        synchronized(this) {
            // Return the state of the Activity reference.
            return (this.getActivity() != null);
        }
    }

    /* Getters and Setters. */
    private final void setActivity(final Activity pActivity) {
        this.mActivity = pActivity;
    }

    private final Activity getActivity() {
        return this.mActivity;
    }

    private final List<IRunnable> getRunnables() {
        return this.mRunnables;
    }

}

구현 측면에서 Pawan M의 위에서 설명한 동작과 일치하도록 수명주기 방법을 적용하도록주의를 기울여야합니다 .

public class BaseFragment extends Fragment {

    /* Member Variables. */
    private ActivityBuffer mActivityBuffer;

    public BaseFragment() {
        // Implement the Parent.
        super();
        // Allocate the ActivityBuffer.
        this.mActivityBuffer = new ActivityBuffer();
    }

    @Override
    public final void onAttach(final Context pContext) {
        // Handle as usual.
        super.onAttach(pContext);
        // Is the Context an Activity?
        if(pContext instanceof Activity) {
            // Cast Accordingly.
            final Activity lActivity = (Activity)pContext;
            // Inform the ActivityBuffer.
            this.getActivityBuffer().onContextGained(lActivity);
        }
    }

    @Deprecated @Override
    public final void onAttach(final Activity pActivity) {
        // Handle as usual.
        super.onAttach(pActivity);
        // Inform the ActivityBuffer.
        this.getActivityBuffer().onContextGained(pActivity);
    }

    @Override
    public final void onDetach() {
        // Handle as usual.
        super.onDetach();
        // Inform the ActivityBuffer.
        this.getActivityBuffer().onContextLost();
    }

    /* Getters. */
    public final ActivityBuffer getActivityBuffer() {
        return this.mActivityBuffer;
    }

}

마지막으로 에 대한 호출에 대해 신뢰할 수없는 Fragment확장 영역 내 에서 간단하게 전화를 걸어 작업을 선언 하십시오!BaseFragmentgetActivity()this.getActivityBuffer().safely(...)ActivityBuffer.IRunnable

그러면 콘텐츠가 void run(final Activity pActivity)UI 스레드를 따라 실행됩니다.

는 ActivityBuffer다음과 같이 사용할 수 있습니다 :

this.getActivityBuffer().safely(
  new ActivityBuffer.IRunnable() {
    @Override public final void run(final Activity pActivity) {
       // Do something with guaranteed Context.
    }
  }
);

답변

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    // run the code making use of getActivity() from here
}